Video: How Amphetamines Work in the Brain & Body

Amphetamines are central nervous system stimulant drugs. They increase certain chemicals in the body, which cause specific psychological and physical effects. This lesson describes how amphetamines work in the brain and the body.2015-05-05

Ashley is an attorney. She has taught and written various introductory law courses.

Amphetamines are central nervous system stimulant drugs. They increase certain chemicals in the body, which cause specific psychological and physical effects. This lesson describes how amphetamines work in the brain and the body.

Amphetamines

Methamphetamine, Adderall, Benzedrine, and Dexedrine. What do these drugs have in common? Some are legal, some are illegal, but all are amphetamines. Amphetamines are central nervous system stimulant drugs.

Because amphetamines are stimulant drugs, they produce extra brain activity, increase alertness, and promote a sense of well-being. Stimulants are sometimes called 'uppers'. They work by energizing the user's nerves and brain. Other stimulants similar to amphetamines include cocaine and the diet drug Phentermine.

Amphetamines increase certain chemicals in the body, which cause specific psychological and physical effects. The effects can be harmful, so proper use of amphetamines must be monitored by a licensed physician.

For that reason, most amphetamines are classified as Schedule II drugs in the United States. That means the federal government classifies the drugs as having a high potential for abuse and potential for severe psychological or physical dependence. Schedule II drugs can be obtained by a written prescription for legitimate medical purposes, but they have heavy restrictions. Schedule II drugs are considered to be the second most dangerous group of drugs.

Let's take a closer look at why amphetamines are dangerous. Let's follow Annie as she takes an amphetamine pill so that we can explore how amphetamines work in the brain and body.

Amphetamines and the Brain

Let's first look at how the amphetamine works in Annie's brain. Amphetamines enhance the effect of neurotransmitters in the user's brain. Neurotransmitters are naturally-occurring brain chemicals that communicate information throughout the brain and body. Neurotransmitters conduct signals between neurons, or nerve cells.

Each person has more than a hundred different neurotransmitters. Different neurotransmitters have different tasks. For example, Annie's brain uses one type of neurotransmitter to signal her lungs to breathe and another to tell her eyes to blink. Note that there are two main categories of neurotransmitters. Excitatory transmitters are those that stimulate the brain. Inhibitory transmitters are those that calm the brain. Amphetamines work on both types.

Amphetamines specifically enhance the effects of three key neurotransmitters. The first is dopamine. This neurotransmitter releases into the brain to elicit feelings of reward and pleasure. For example, dopamine releases into Annie's brain when she laughs at a funny joke or when she eats a delicious meal. Dopamine works as both an excitatory and an inhibitory transmitter. Amphetamines influence dopamine more than any other neurotransmitter.

The second is serotonin. This neurotransmitter influences mood, appetite, and anger. Serotonin affects some important body functions, including sleep cycles, body temperature, and blood pressure. Research shows that serotonin releases into Annie's brain when she exercises or is exposed to bright light. Serotonin is an inhibitory transmitter that decreases anxiety and improves mood.

The third is noradrenaline, also called norepinephrine. This neurotransmitter is responsible for the body's fight or flight response. Noradrenaline helps produce the rush of adrenaline that gives the body its sudden alertness and energy. It automatically increases the heart rate, triggers the release of glucose from energy stores, and increases blood flow to skeletal muscle. For instance, Annie might feel a sudden rush of noradrenaline when she sees a mouse run across her path. Noradrenaline is an excitatory transmitter.

Euphoric Effect

When Annie takes the amphetamine, all three of these neurotransmitters are quickly released into her brain. Imagine feeling reward, pleasure, improved mood, and a sudden rush of adrenaline all at once! When amphetamines are taken in high doses, usually above the prescribed amount, the user can experience euphoria, which is an extreme feeling of happiness and well-being. Illegal amphetamines are also designed to produce this effect.

Normally, the neurotransmitters are released and then recycled back into the neurons. Annie's good feeling fades away. But amphetamines temporarily prevent the neurotransmitters from being recycled. This makes the euphoria last longer. Depending on the type of amphetamine and how much is consumed, the euphoric effect can last anywhere from 4 to 24 hours.

When the euphoric effect ends, it's known as a crash. The neurotransmitters are suddenly no longer stimulated, which can lead to depression, fatigue, and even suicidal thoughts. Some users continue to abuse amphetamine in order to avoid this crash.

The euphoric effect on the brain, and the attempt to avoid the crash, can lead to psychological dependence. Psychological dependence is a perceived need for a substance, based on a strong compulsion or urge to use the substance. For example, Annie's body may not physically depend on the drug, but her mind tells her she needs it. Psychological dependence normally requires rehabilitation in order to recover. Rehabilitation teaches the skills and coping techniques required to ward off desires and cravings for the substance.

These physical outcomes can be dangerous. Less blood and oxygen is able to reach the user's organs, so the user is at a high risk for heart attack or stroke. People with pre-existing heart conditions shouldn't use amphetamines, since an increase in blood pressure or an elevated heart rate can be fatal.

If Annie becomes a regular user of amphetamines, her use could lead to physical dependence. Physical dependence refers to the human body's reliance on a substance to the point that the body cannot function without it. When Annie's body goes without the drug, her body might experience withdrawal effects such as nausea, vomiting, headaches, and overall pain. These physical symptoms tell Annie she needs more of the drug in order to function. This type of dependence normally requires a detoxification process, which is a method for slowly weaning the body off a substance.

Lesson Summary

Let's review. Amphetamines are central nervous system stimulant drugs. Stimulant drugs produce extra brain activity, increase alertness, and promote a sense of well-being. Amphetamines enhance the effect of three neurotransmitters in the user's brain. Neurotransmitters are naturally-occurring brain chemicals that communicate information throughout the brain and body. They conduct signals between neurons, or nerve cells.

The three neurotransmitters are:

Dopamine, which releases into the brain to elicit feelings of reward and pleasure. It's an excitatory and inhibitory transmitter.

Noradrenaline, which is responsible for the body's fight or flight response. It's an excitatory transmitter.

In combination, the enhancement of these brain chemicals can cause euphoria, which is an extreme feeling of happiness and well-being.

Physically, amphetamines cause:

An increase in blood pressure

An elevated heart rate

Constricted blood vessels

Increased blood glucose levels

Decreased appetite

An opening of breathing passages

Most amphetamines are Schedule II drugs, meaning the federal government classifies the drugs as having a high potential for abuse and potential for severe psychological or physical dependence. Psychological dependence usually requires rehabilitation. Physical dependence normally requires detoxification.

Summary:

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